1. Field of Invention
Embodiments of the invention relate generally to methods and systems for managing facility power and cooling.
2. Discussion of Related Art
Centralized data centers for computer, communications and other electronic equipment have been in use for a number of years, and more recently with the increasing use of the Internet, large scale data centers that provide hosting services for Internet Service Providers (ISPs), Application Service Providers (ASPs) and Internet content providers are becoming more prevalent. Typical centralized data centers contain numerous racks of equipment that require power, cooling and connections to external communications facilities. In modem data centers and network rooms, the increased density of computing equipment used in these facilities has put strains on the cooling and power systems of the facilities. In the past, typical power consumption for each equipment enclosure in a data facility was on the order of 1 kW. With the use of server blades and other high power density equipment in equipment racks, it is not uncommon for an equipment rack to have a power draw of 10 kW or even as high as 25 kW.
Typically, the power consumed by computer equipment is converted to heat and typically, the cooling requirements of a facility are determined based on the power requirements of the facility. Typical data centers utilize air plenums under raised floors to distribute cooling air through a data center. One or more computer room air conditioners (CRACs) or computer room air handlers (CRAHs) are typically distributed along the periphery of the data room, and these units draw return air from the room or a ceiling plenum and distribute cooling air beneath the raised floor. Perforated tiles may be placed in front or beneath racks of equipment to be cooled to allow the cooling air from beneath the floor to cool equipment within the racks.
Several tools are available to assist a data center designer in configuring a layout of a data center to provide necessary power and cooling to equipment to be located in the data center. These tools typically assist a designer in determining total power requirements and accordingly overall cooling requirements for a data center. In addition, these tools may assist a designer in determining optimum equipment layout and proper sizing of power cabling and circuit breakers.
While existing tools provide a designer with detailed layout information regarding power distribution, these tools typically provide far less help in determining cooling needs for a facility. Advanced programs that use computational fluid dynamics (CFD) may be used to model the cooling design of a facility, but the use of such programs is extremely limited due to the complexity of the programs, which results in their use being prohibitively expensive and time consuming. U.S. Pat. No. 7,313,503 to Nakagawa et al describes an automated system for designing a cooling system for a facility. In the system of Nakagawa, the facility is divided into a number of pre-characterized cells (such as a cluster of racks) over which the response of various parameters, such as maximum temperature, are known based on key parameters. The system uses built-in cell to cell interaction rules to predict overall thermal performance and to optimize equipment layout. While this system may offer some improvements in speed over a full CFD analysis, it is limited to the use of pre-characterized cells, and does not provide analysis below the cell level. Also, the cells must be characterized using, for example, a CFD analysis or physical testing.
Programs and systems such as those described above provide idealized results for the cooling performance of a facility and often fail to account for situations which often occur in real life installations, which can dramatically affect the cooling performance of a data center. For example, in a facility using a raised floor, the absence of one or more floor panels, or the misplacement of one or more perforated floor panels can greatly affect the cooling performance of the data center and cause the actual performance to vary greatly from a calculated idealized performance. Further, the degradation in performance of one or more air conditioning units can drastically change airflow and cooling characteristics of a facility.
The inability to properly analyze the cooling performance of a facility typically causes a data center designer to over design the facility from a cooling perspective, which results in the facility to be more expensive and less efficient.
In existing data centers, it is often desirable to replace equipment with upgraded equipment and/or add new equipment to existing enclosures in the facility. Several tools exist which enable a manager of a data center to monitor power usage in a facility. These tools include the InfraStruxure™ Manager product available from American Power Conversion Corporation of West Kingston, R.I.
With the increasing cooling and power requirements of computer equipment, it is desirable for a data center manager to determine if there is adequate power and cooling available in the facility before new or replacement equipment may be added. Typically, a data center manager may know, or can determine, if the total cooling capacity of the data center is sufficient for the total power draw. However, hot spots in a facility may develop, particularly where high power density equipment is used, and it may not be enough to merely analyze cooling capacity at the facility level. To attempt to identify hot spots, a data center manager may resort to manual temperature measurements throughout a facility and try to implement fixes to correct the hot spots. Such fixes may involve a rearrangement or replacement of perforated floor panels, a rearrangement of enclosures, and/or adding additional cooling capacity. In any case, these fixes are typically done on a trial and error basis, and while some hot spots may be eliminated, the fixes may cause other hot spots to arise due to a redirection of the cooling air in the facility. This trial and error approach can lead to unexpected failures of equipment, which is unacceptable in critical data centers. To avoid such failures, data center managers typically over design facilities and fail to use facilities to their full capacity.